Throughout its history the Kingdom of Mercia was a battleground between conflicting religious ideologies. Early history It is likely that the Anglian occupation of Mercia saw the displacement of, or integration with, Sub-Roman British tribes. There is a possibility that some of these British Christian communities survived the Anglo-Saxon occupation: Richard Fletcher mentions Much Wenlock as a possible candidate. The first kings of Mercia were pagans, and they resisted the encroachment of Christianity longer than those of other kingdoms in the Anglo-Saxon Heptarchy. Placenames like Wednesfield and Wednesbury perhaps suggest that the worship of Woden was particularly prominent, and that there was a cluster of late pagan practice near Birmingham: there are no surviving toponyms relating to Thunor, for example, although Tiw may be connected to Tyseley, Tysemere and Tysoe. Similarly the Old English word weoh (altar) is found as a root for several Mercian placenames including Weeford near Lichfield. Mercian rulers remained resolutely pagan until the reign of Peada in 656, although this did not prevent them joining coalitions with Christian Welsh rulers to resist Northumbria. The first appearance of Christianity in Mercia, however, had come at least thirty years earlier, following the Battle of Cirencester of 628, when Penda incorporated the largely Christian West Saxon territories of the Hwiccas into his kingdom. The Mercian Supremacy Reign of Penda The conversion of Mercia to Christianity occurred in the latter part of the 7th century, and was carried out almost entirely by Northumbrian and Irish monks of the Celtic Rite. Penda remained pagan to the end, but by the time of his defeat and death, Mercia was largely surrounded by Christian states. As such, it was excluded from many of the networks of diplomacy and alliance that extended through Western Europe, as these generally involved dynastic marriages and ecclesiastical negotiation. Christianity gained a foothold in Mercia precisely through these channels. Part of the price of Oswiu's support for Peada as sub-king of the Middle Angles, during the period of Mercian eclipse, was that Peada marry Oswiu's daughter, Alchflaed, and accept her religion. Diuma, an Irish monk and one of Oswiu's missionaries was subsequently ordained a bishop—the first to operate in Mercia. Peada founded an abbey at Medeshamstede, in modern Peterborough, as earnest of his support for the Church. Bede tells us that Penda respected the Christians and even allowed them to operate more widely in Mercia. However, it seems that